"There's nothing in Catholic teaching or law that would prevent a group from having a seder meal to teach the faithful the origins of our own Mass, which comes from the seder." (Bishop Edward J. Slattery)
In fact, the Haggadah, the liturgy used at seders, began to be formulated in the Talmudic Era, centuries after Christ's Last Supper. The Haggadah as it exists today--as it is now celebrated in Catholic parishes around the world--dates only to the 13th century A.D. The traditional Mass does not "come from the seder," although it is accurate to say that parts of the Novus Ordo Mass of 1969 do. I doubt that Bishop Slattery wants this distinction to be known. As we have seen from other modern prelates of high position, including the Pope, they want Catholics to believe that rabbinic tradition is an authentic continuation of the religion of the faithful Israelites of the Bible and for Catholics to involve themselves in these traditions. There could be no worse deception than this, as Pope Innocent IV observed, through the rabbis' traditions, they render souls utterly alien from the law and the prophets, a fact which was later documented so thoroughly by Johannes Eisenmenger in his masterwork, Entdecktes Judenthum that no defense, other than censorship and ad hominem, has even been attempted against it.
For this rabbi enabler to be offering a traditional Latin Mass in the place of the sex predator enabler, Cardinal Castrillon Hoyos, is no less a scandal. Protect your children, body and soul, from these treacherous men.